Rosin size



Dec. 13, w. H' HARDlNG ET AL ROSIN SIZE Fned lawn 17, 1931 l Il MII nl" t "mw III Patented Dec. 13, 1932 UNITED STATES PATENT OFFICE WILLIAM I-I. HAB/DING, 0F FLUSHING, NEW YORK, AND SIDNEY V. BURROWS, OF :BOS-

TON, MASSACHUSETTS, ASSIGNORS TO THE KALBFLEISCH CORPORATION, OF.NEW YORK, N. Y., A CORPORATION OF DELAWARE ROSIN SIZE Application filed March 17, 1931.

sion having a high percentage of free rosin.V

More recently it has come to be realized that there are certain advantages in the use of a low free rosin size, that is, a size in which not more than substantially 22% `and preferably less, of the total rosin, as determined by titration, remains unsaponiiied. It is found that it is cheaper to make a low free rosin size inasmuch as less rosin may be used to obtain the same or better results than those given by a high free rosin size. Also there is some indication that a harder finished paper can be obtained with a low free rosin size. However, the commercial attempts which have been made to obtain a low free rosin sizeof less than 22% unsaponifled rosin, as determined by titration. have been unsatisfactory and the processes followed of such a nature as to be commercially unsuccessful.

Rosin size is normally made by cooking rosin with soda ash. The proportion of soda ash used varies7 dependent upon thetype of rosiny and other conditions. The rosin ordinarily consists of from 86 to 92 per cent abietic acid7 the balance being unsaponifiable matter or resene. The soda ash or other suitable alkali reacts with the abietic acid and forms a rosin soap. Under ordinaryvprocessing conditions thev usual rosin size containssomewhat more than 22% of the unsaponilied rosin. In order to more completely saponify the abietic acid or saponiable portion of therosin, it has been necessary to use large excesses of soda ash or other alkali and to cook the vmix for a prolonged period. It hasbeenfound that when this procedure is attempted the mix becomes gelatinous and'is exceedingly difficult to handle. The masshas become so viscous in many cases that pumping of it is impossible and the apparatus and lines must be Serial No. 523,274.

completely disassembled to remove the gelatinous mass. In certain instances the mix has been cooked under pressure in' order to more completely saponify the available saponifiable rosin, but such equipment is expensive and increases the cost of the size to such an extent as to make its use commercially unfeasible. Attempts have been made to hasten and increase the saponifcation by the use' of caustic alkalies and ammonia, sometimes alone or in combination with soda ash. j However, up to the present time it has been impossible to manufacture successfully commercially a low free rosin size of the type in which the abietic acid is substantially completely'saponiied. .s One of the primary objects of our invention is to obtain a simple and easy method for making a rosin'size by which the abietic acid present may be substantially completely saponiied.V

Another object of our invention is to obtain a method by which a low free rosin size `may be made without gelatinization.

A further object of our invention is to obtain a simple and inexpensive apparatus for manufacturing a size having a rosin substantially completely saponified. f

Other objects and dvantages of our invention will appear from the followingdrawing, in which Figure l represents diagram- Ymatically an apparatus suitable for carrying out our process, and Fig. 2 is a detailview ofthe emulsilier. v 3

Referring more parti ularly to the drawing, reference character l 'designates a container for holding a rosin-size mix. The container 2 holds-a caustic solution. Al pipe or conduit 3 controlled. by the valve 3" leads 0E from the container `1 and has in it an orifice plate 4 lhaving the orifice 4. This pipe connects with the pipe 5 which leads off from the container 2 and which is controlled by the valve 5j. These pipesl and 5 combine lto form the pipe 6. The pipe 7 controlled by the valve 7 is connected to a sourceV of water and is joined to the pipe 8 controlled by the` valveS which pipe may be connected to a sourceof steam or hot water. These two pipes 7 and 8 combine to form the pipe 9 and it is seen that by proper adjustment of the valves 7 and 8 a mixture of steam and water can be made so that the line 9 will carry hot water. This line is combined with pipe 6 to form the ppe 10 which leads to the emulsitier 11. The eniulsiier is preferably of the form as shown in detail in Figure 2. Steam preferably, although hot liquidvmay be used, is admitted into this femulsifier through the ppe 12 controlled by the valve 12 and a jet'of steam is direct-ed into the size solution passing through the constricted portion 14 by the nozzle 1.3. A turbulent effect is produced and an emulsion formed in which all of the constituents are thoroughly mixed. This mixture is discharged into the container 15 from which it may be drawn for use in the beater or otherwise. Suitable heating means may be employed in connection with the various containers to maintain the liquids at desired temperatures. A washout connection 16 controlled by the valve 16 is shown connected to the line 5.

The operation of our process consists in starting the emulsifier 11 in the normal manner. The orificeplate 4 in the size line 3 is provided with an Vorifice 4 suitable to permit the passage of that amount of size which may be mostV efficiently emulsified by the emulsiier 11. The rate of flow of caustic from the tank 2 through the line 5 to the emulsifier is then adjusted so that it is constantly yproportional to the flow of size through the orifice plate 4. The amount of caustic added may be ixed so that substantially all of the unsaponiied saponifiable rosin will be saponiied. The proper amount of caustic solution to accomplish this result may be determined by experiment. Hot water is added through the line 9 to the mix. This hot water may be obtained by admitting steam through the line 8 to the Water entering through the .line 7 .The amount of hot water added to the size before entering the emulsilier is, of

sifying conditions and the type of the emulsitied size desired. This water would ordinarily be at 140 F. The rosin size is preferably maintained at about 160o F. Upon entering the emulsiier the steam passing through the nozzle 13 would cause an extremely turbulent ietfect thoroughly mixing the caustic, the rosinvsize and the hot water and 'further heating the mix to approximately 175 to 180 F. The control of addition of caustic solution to rosin size is preferably Vso arranged that when the size in the container 1- is completely used up the caustic `solution in the container 2 will be also used up. The system may then be washed out by means of the washout line 16.

yIt can be seen that the caustic alkali comes in contact with the rosin size substantially at the point of maximum temperature and agitation, and the reaction, therefore, of the It is possible, of course, to so adjust the` amount of caustic alkali added to the size passing through the emulsier that only a portion of the free rosin or free abietic acid vpresent in the size will be saponilied. Thus a size may be obtained which will contain a smaller percentage of free rosin than that obtainable by the prior methods and yet one which will have a certain desired small percentage of free rosin.

As we have pointed out before a free rosin content, as determined by titration, of a normally low free rosin size as known in the prior art is from 22 to 26% of'total rosin. The unsaponifiable content of ordinary rosin varies between 8 and 14% and will average probably about 10%. In the present process it has been found that the percentage of unsaponiiied material may be reduced from 22 to 26% to 12 to 16%. In other words, the percentage of unsaponifed saponiiable matter may be reduced from approximately 50 to 90%.

-We have also found that by properly adjusting the caustic solution furnished to the emulsifier so that a greater quantity used than that necessary to saponify all the saponifable matter present that 4,an emulsion can be obtained in which there is considerable ,free caustic and in which the percentageof VThe elimination of the alkaline treatment removes one possible source of trouble in the beater.

It is seen, therefore, that by the utilization of our process and apparatus it is possible to obtain a rosin size in which the unsaponified saponiliable content has been substantially eliminated or at least lowered below the IUI percentage normally found in an ordinary low free rosin size. This has been accomplished by a comparatively simple apparatus and one in which none of the former pro` cessing difficulties are present. A rosin size containing substantially no unsaponified saponiiable matter can be made without use of `pressure equipment and without gelatinization during the process or other processing diiiiculties. Furthermore, by our process the size is furnished ready for use and the necessity for expensive cooking equipment iseliminated. While we have shown only a specific application of our process, it will be apparent to those skilled in the art that various modica'tions can be made without departing from the spirit of our invention.. For example, the caustic solution may be added directly to the emulsiiier. Other strong alkalies may be used than caustic soda, for example, potash or ammonium hydroxide. rl`he rosin size with which the regulated quantity of caustic solution is to be mixed may contain a considerable percentage of free rosin. It is not necessary that the starting size be what has heretofore been known as ordinary low free rosin size. We, therefore, do not wish to be limited by the specification and drawing. but only by the appended claims.

What we claim is 1. A method for making a low free rosin size comprising substantially simultaneously subjecting a rosin size having a free rosin content of greater than 22%, as determined by titration, to great agitation with the addition of heat and substantially simultaneously adding a strong alkaline solution.

2. A method for making'a size having an unsaponified saponiable rosin content of less than 10%, as determined by titration,

comprising adding an alkaline solution to aV free rosin size having a free rosin content of greater than 20%, as determined by titration, and emulsifying the mix with the simultaneous addition of heat.

3. A method for making a size having a free rosin content of less than 20%, as determined by titration, comprising adding a strong alkaline solution to a free rosin size having a free rosin content of greater than 20%, as determined by titration, and emulsifying the mix with the simultaneous addition of heat.

4. A method for substantially eliminating the unsaponified saponifiable content of a rosin size comprising continuously adding a regulated quantity of a caustic solution to a continuously regulated quantity of rosin size and emulsifying during the addition of heat.

5. A method for making a rosin size having a percentage of unsaponified saponiable matter of less than 10% comprising subiecting a rosin size having a relatively high free rosin content to great agitation, and substantially simultaneously vadding a caustic solution.

6. A method for making a low free rosin size comprising passing a rosin size having a relatively high free rosin content through an emulsifying injector and adding a caustic solution at substantially the point of greatest turbulencv and heat.

In testimony whereof, I have signed mv name to this specification this 13th day of March 1931.

WILLIAM H. HARDING.

In testimony whereof, I have signed my name to this specification this 14th day of March 1931.

SIDNEY V. BURROWS. 

